This invention relates to valve mechanisms. More particularly, it provides a valve seat cleaning mechanism to remove dirt particles that may be on a valve seat and which would otherwise interfere with correct operation of the valve.
The present invention utilizes a flexible disk for the purpose of wiping away dirt particles from the valve seat. That disk is attached to a valve head of resilient material, which head makes ultimate contact with the valve seat in the closed position of the valve to provide the valving action.
The use of a flexible disk in a valve mechanism is known. In U.S. Pat. No. 3,548,868 issued Dec. 22, 1970 to Mullaney, III, a flexible auxiliary valve seat is disclosed. The flexible disk shown in that patent is not for valve seat cleaning but rather is for the formation of a valve seal. U.S. Pat. No. 2,977,974 to Browne which issued Apr. 4, 1961 discloses a valve head utilizing a rubber disk. While a cleaning action is described in the patent, the disk serves as the primary valve sealing member. Kushida U.S. Pat. No. 3,841,347 which issued Oct. 15, 1974 is similar to the Browne patent in disclosing a flexible disk which provides a valve cleaning action. That disk, however, forms the principal seal in the valve.
In the present invention, a valve member is utilized that includes a valve head of resilient material in the shape of a frustum of a cone. A flexible circular disk is positioned against the valve head, and particularly that end of the valve head which is of lesser diameter than the other end. The diameter of the flexible disk is somewhat greater than the diameter of the valve head end against which it is positioned. In this fashion a wiping member is formed which makes initial contact with a valve seat when the valve head is being moved into a valve closed position. Impurities on the valve seat are thus wiped off by the flexible disk. Further movement of the valve head provides for the sealing between the valve head and the valve seat. In this position of the valve head, the flexible disk does not form any part of the sealing mechanism. In fact, puckering of the flexible disk takes place so that no seal is formed.
The invention will be more completely understood by reference to the following detailed description, which is to be taken in conjunction with the appended drawing.